This invention pertains to chains, and, in particular, to a side-flexing chain with wheels for supporting the weight of the chain and for guiding the chain.
Many types of chains are known in the art. Some chains have support wheels to carry the weight of the chain and guide wheels to guide the chain as it travels along a track. However, there are several problems with these chains.
The chains of this type which existed prior to the present invention could only be driven by a sprocket lying below the chain, meaning that less than half of the chain could be functioning to carry products at any given time, and the rest of the chain would be passing over the sprocket or on a return run. The cost of the extra chain and the cost of continually moving the extra chain are substantial and are essentially wasted expenses.
If the conveyors using these chains get to be too long, the chain has to be broken into pieces, each having a separate drive. The cost of the drive and its related controls is usually about one-third of the cost of the conveyor, so breaking the conveyor into parts with separate drives is very expensive.
The known chains of this type can only be pulled--they cannot be pushed. If they were pushed, they would buckle and wedge against their guide tracks.
The known chains of this type can only be driven by a sprocket, which must be at the head end of the conveyor. This is often an inconvenient location for the drive, as the ends of the conveyor are often crowded with other devices. It would be very desirable to move the drive to another part of the conveyor, but, prior to the present invention, that has not been possible.
The known chains of this type all require a catenary or some other arrangement to keep the chain tight and to compensate for any stretching of the chain during operation.
The known chains of this type generally do not provide good bearing surfaces for the joints of the chain which flex, which causes the chains to tend to wear at those joints.